Hi,
Is there a way to get this to typecheck?
(: cars : (All (A) (Listof (Listof A)) -> (Listof A)))
(define (cars ls)
(map car (filter cons? ls)))
By looking at the error, it seems the problem is that it is impossible to map car on a list of lists:
> (map car '((1)))
Type Checker: Polymorphic function map could not be applied to arguments...
Thanks,
-- Éric